Rust preventive composition



3,006,850 Patented Oct. 31, 1961 3,006,850 RUST PREVENTIVE COMPOSITEON Ellis K. Fields, Chicago, lll., assignor to Standard Oil Company, Chicago, Ill., a corporation of Indiana No Drawing. Filed Oct. 31, 1956, Ser. No. 619,384 9 Claims. (Cl. 25246.6)

' with water or steam.

in various equipment in which Water and/ or steam is used, or which may become contaminated with water or steam during service or storage, corrosion and/ or rusting of the metal parts, particularly the ferrous metal parts, is encountered causing material damage to such equipment. For example, in the operation of steam turbines, rusting or corrosion of the metal parts of such systems is a serious problem, and hence, prevention or inhibition of such corrosion or rusting is highly important. Similar problems exist in the lubrication of certain types of marine engines.

The present invention is also applicable to anti-rust or slushing compositions for the protection of metals against atmospheric corrosion and/ or rusting. Such anti-rust or slushing compositions are applied to metallic articles to be stored or for shipment to prevent rusting and/or corrosion thereof. Similarly, fabricated metallic articles and finished or semi-finished metal stocks destined for shipment by rail or by water are protected against attack by moisture by coating such materials with anti-rust or slushing compositions.

Accordingly, it is an object of the present invention to provide a composition which will efli'ectively inhibit or prevent the rusting =and/ or corrosion of metallic surfaces.

Another object of the invention is to provide a composition which will effectively inhibit or prevent the rusting and/or corrosion of metallic surfaces which come in contact with water and/ or steam.

A further object of the invention is to provide a turbine oil which will effectively inhibit the rusting and corrosion of the metal surfaces of the system which come in contact with water or steam. Still another object of the invention is to provide a lubricant composition which will effectively inhibit or prevent the corrosion and/ or rusting of metal surfaces of equipment employing such lubricant, particularly in equipment in which steam or water may be present.

Still another object of the invention is to provide a slushing composition which will prevent or inhibit the rusting and/ or corrosion of metal surfaces.

I have discovered that the foregoing objects can be attained by employing a composition comprising a major proportion of an oleaginous liquid vehicle and from about 0.0001% to about 5.0%, preferably from about 0.001% to about 1.0%, of the oil-soluble acidic hydrolyzed reaction product of a phosphorus sulfi'de and a medial olefin having the general structural formula where n is an integer of 8 to 20 inclusive. The medial olefins consist of two long straight hydrocarbon chains coming from each end of a carbon to carbon double bond, as above illustrated. Such olefins can be prepared by the catalytic decarboxylation of long chain fatty acids to give the corresponding ketone which is then reduced to the carbinol and dehydrated. Specific examples illustrating medial olefins are l l-tricosene and 17-pentatriacontene, derived from lauric acid and stearic acid respectively, 13- heptacosene, and 9-nonadecene.

In preparing the reaction product of the medial olefin and the phosphorus sulfide, such as P 8 P 8 and preferably P 8 (P 8 the olefin is reacted with the phosphorus sulfide preferably in the mole ratio of 2:1. It is advisable to use as much phosphorus sulfide as can react with the olefin in order to fully utilize all of the olefin; however, the use of more phosphorus sulfide than required for by the molar ratio of 2:1 results in unused sulfide which confers no particular advantage. The reaction is carried out at a temperature of from about 325 F. to about 500 F., preferably about 450 F. for periods of from 0.5 hour to 7 hours, and preferably about 1.5 hours. The resultant reaction product is hydrolyzed by steaming at about 300 F. for about 3.5 hours, and the hydrolyzed product freed of any phosphoric acid or lower organic acids by washing with water or by contacting with filtration clay, such as Attapulgus clay fines.

The following examples are illustrative of the present invention:

Example I A mixture of 644 g. (2 moles) ll-tricosene and 222 g. (1 mole) P 8 was stirred and heated at 450 F. for 1 hour. All the P 8 had reacted by this time. The product was steamed at 300 F. for 3 /2 hours, contacted with g. Attapulgus clay fines at 300 F. for 1 hour, and filtered through Celite, giving 722 g. brown viscous product containing 10.55% sulfur, 6.64% phosphorus, having a molecular weight of 930, an acidity of 94.55 mg. as KOH, and a viscosity of 553.6 SSU at 210 F.

Example II A mixture of 735 g. (1.5 moles) 17-pentatriacontene and 166 g. (0.75 mole) P 8 was stirred at 450 F. for 1 /2 hours, steamed at 300 F. for 3 /2 hours, cooled, diluted with 800 ml. hexane and 500 m1. isopropyl ether, washed with 2 liters water, and evaporated, giving 745 g. brown, very viscous product analyzing 9.87% sulfur, 4.72% phosphorus, 1200 molecular weight, and acidity of 61.29 mg. as KOH.

Although the product described herein can be suitably employed in oleaginous compositions in general as hereinafter more fully described, particularly to inhibit or prevent rusting and/or corrosion, for the purpose of exemplifying the present invention the same will be described as applied to steam turbine lubricants for which highly refined oils having Saybolt Universal viscosities at 100 F. of from about 100 seconds to about 250 seconds are employed.

With the advent of drastic refining treatments to produce more highly refined turbine oils having improved nonsludging and emulsification properties, certain components of such oils, responsible for the wetting and therefore rust inhibiting properties of the oil are, however, removed. As a result, such oxidation stable oils, produced by the drastic refining treatments, are inferior with respect to rust inhibiting qualities. Rusting in steam turbine systems is usually encountered in the upper portions of the oil reservoirs and other parts of the systems by virtue of 3 droplets of water coming in'contact with the metallic surfaces and displacing any oil which may be present thereon. Oil will provide adequate protection against such rusting only if it wets the metal surfaces preferentially as compared with Water. As the rusting in steam turbine systems progresses, the iron oxides formed may scale oif and be carried in suspension in the oil, often scoring bearings, plugging oil lines and frequently causing faulty operation of delicate governor parts. The need for non-rusting turbine oils is therefore great. The rust inhibiting characteristic of turbine oils containing such additives is demonstrated by the following tests:

Three hundred cubic centimeters of the oil to be tested are placed in a 400cc. lipless glass beaker and heated to 140 'F. in an oil bath and the oil stirred with a stirrer maintained at about 1000 rpm. When the temperature of the oil sample reaches 140 F. a cleaned strip of cold rolled steel is suspended in the oil and stirring continued for 30 minutes to insure complete wetting of the steel specimen. Thirty cubic centimetersof distilled water are then carefully added by pouring it down the .side of the beaker and stirring continued for twenty-four hours. At the 7 end of this period the specimen is removed from the beaker, washed with naphtha and visually inspected for the presence of rust. The method of carrying out this test is fully described in the A.S.T.M. Manual of 1953, page 292, and identified as A.S.T.M. method D665-53T. Another rust inhibiting testis the so-called film tenacity test which is carried out as follows:

At the end of the 24-hour period of the A.S.T.M. D665- 53T, the oil in the beaker is replaced by 330 cc. distilled water, and stirring-continued at 140 F. for another 24 hours. At the end of this period the specimen is rinsed with acetone and visually inspected for the presence of rust. Thistest is particularly severe since there is no reservoir of oil containing the inhibitor. It measures the tenacity of the inhibitor film on the metal surface and the ease with which it is removed bywater.

The reaction products-of Examples I and II in a turbine oil base stock, namely in highly refined petroleum oil having a Saybolt Universal viscosity at 100 F. of about 150 .seconds, were subjected to the above tests; For the purpose of comparison, similarly prepared reaction products of P 8 (P 8 and other olefins were also tested. These reaction products were:

Example III Hydrolyzed reaction product of P 3 and octadecene. Product analysis:

Sulphur 9 7 PhOSphOUlQ Acidity mg.. as KOH 99,72, Molecular Weight Example IV Hydrolyzed reaction product of P 8 and a polybutene having a mean molecular weight of about 330. Product analysis: I

Sulphur 6.94% Phosphorus 8.8 Acidity mg. as KOH 155.5. Molecular weig 726. Saybolt Universal viscosity at 210 F sconds 5 35 6.

Example V Hydrolyzed reaction product of P 3 and a polybutene having a molecular weight of about 1010. Product analysis:

The results of the rust preventive tests are given in the following table:

The above data demonstrate the superior rust preventing properties of the hydrolyzed reaction products of phosphorus sulfide and a medial olefin' as compared with similar reaction products of other olefins.

While the herein described reaction products are especially well adapted fonuse in turbine oil compositions they canbe used in small proportions, namely up to about F 1% in a wide variety of .oleaginous bases, such as, by way of illustration, hydrocarbon oils, i.e. petroleum oils' and synthetic hydrocarbon oils, aliphatic dicarboxylic acid esters, silicone polymers, 1,24polyoxypropy1ene alipha-tic ethers such as described in US. 2,488,644, esters of dihydroxythioethers such as described in U.S..2,451,-' 895 and other oleaginous compounds. Illustrative of the .mediafin which. these additives can be employed are the following: v

Motorfuels; for example, automobile or aviation gasolines, tractor fuels, diesel engine fuels, alcohol-containing motor fuels;

Lighting andheating fuel-s; kerosene stove oils, stove and lighting nap hthas, furnace oils, fuels;

Solvent naphthas, cleaner naphthas, such as Stoddard solvent, V.M. and P. naphthas, hydroformed naphthas;

Lubricating and dielectric oils; motor oils, diesel 'oils, aviation engine oils, marine engine lubricants, gear oils, oil field machinery lubricants, ice-machine oils, steam cylinder lubricants, transmission oils,'soluble oils, textile oils, cutting oils, turbine oils, insulating oils;

Lubricating greases; stable gel-like or solid dispersions of metal soaps in hydrocarbon oils;

Protective coatings; Slush'ing oils and greases in which part or all of the hydrocarbon oil may be replaced by metal soaps, pitches, tars,- asphalt, rosin, etc.

The herein described coin-positions can in addition contain V.I. improvers, viscosity-increasing agents, bloom producing-agents, extreme pressure agents, anti-oxidants, dyes, andant-i-knock agents, as well as other rust or corrosion inhibiting agents such as, toil-soluble alkali metal 'sulfonates, for example, sodium mahogany soap, etc., provided only that these additional agents do not enter into appreciable chemical reaction withthe described condensation products .or precipitate them from the oils to which .they have been added.

Thus, in turbine oils, we can add, in addition to the described condensation products, an antioxidant such as the polyhydric phenols and their a-lkyl derivatives, for example, catechol, tertiary .butyl-catechol, octyl catechol, etc. Other eifective antioxidants include beta-naphthol, amyl beta-naphthol, octyl beta-naphthol, lauryl beta-naphtho l, alpha-naphthol, amyl alpha-naphthol, N-phenyl alphanaphthyl-amine, -di-alpha-naphthyl-amine and the like. The antioxidant may. suitably be used in a proportion in the rangeof about 0.001% to about 0.25% (by weight) based on theoil. V I

Percentages given herein and in the appended claims are weight percentages, unless otherwise stated.

I claim: ,1. A rust preventivecomposi-tion comprising a major proportion of an oil and from about 0.000-1% to about wherein n is an integer of 8 to 20, said hydrolyzed reaction product being obtained by reacting medial olefin with a phosphorus sulfide, in the mole ratio of about 2:1 respectively, at a temperature of from about 325 F. to about 500 F. and hydrolyzing the resultant reaction product.

2. The rust preventive composition of claim 1 in which the medial olefin is ll-tricosene.

3. The rust preventive composition of claim 1 in which the medial olefin is l7-pentatriacontene.

4. A rust preventive composition comprising a major proportion of a hydrocarbon oil and from about 0.000l% to about 5.0% of an oil-soluble acidic hydrolyzed reaction product of a phosphorus sulfide and a medial olefin having the general structure wherein n is an integer of 8 to 20, said hydrolyzed reaction product being obtained by reacting medial olefin with a phosphorus sulfide, in the mole ratio of about 2:1 respectively, at a temperature of from about 325 F. to about 500 F. and hydrolyzing the resultant reaction product.

5. A rust preventive composition comprising a major proportion of a hydrocarbon oil and from about 0.0001 to about 5% of an oilsoluble acidic hydrolyzed reaction product of phosphorus pentasulfide and 11-tricosene, said hydrolyzed reaction product being obtained by reacting ll-tricosene with phosphorus pentasulfide in the mole ratio of about 2:1 respectively, at a temperature of from about 325 F. to about 500 F. and hydrolyzing the resultafit reaction product.

6. A rust preventive composition comprising a major proportion of a hydrocarbon oil and from about 0.0001% to about 5% of an oil-soluble acidic hydrolyzed reaction product of phosphorus pentasulfide and 17-pentatriacontene, said hydrolyzed reaction product being obtained by reacting 17 -pentatriacontene with phosphorus pentasulfide, in the mole ratio of about 2:1 respectively, at a temperature of from about 325 F. to about 500 F., and hydrolyzing the resultant reaction product.

7. A rust preventive composition comprising a major proportion of a hydrocarbon oil and from about 0.001% to about 1.0% of the oil-soluble acidic hydrolyzed reaction product of phosphorus pentasulfide and a medial olefin having the general structure H-C(CH2)n+iCH in which n is an integer of 8 to 20, said hydrolyzed reaction product being obtained by reacting said medial olefin with phosphorus pentasulfide, in the mole ratio of about 221 respectively, at a temperature of from about 325 F. to about 500 F., and hydrolyzing the resultant reaction product.

8. The rust preventive composition of claim 7 in which the medial olefin is ll-tricosene.

9. The rust preventive composition of claim 7 in which the medial olefin is l7-pentatriacontene.

References Cited in the file of this patent UNITED STATES PATENTS 2,316,088 Loane Apr. 6, 1943 2,516,119 Hersh July 25, 1950 2,534,217 Bartleson Dec. 19, 1950 2,640,053 Hill May 26, 1953 2,688,612 Watson Sept. 7, 1954 2,715,612 Home Aug. 16, 1955 2,759,920 Watson Aug. 21, 1956 

1. A RUST PREVENTIVE COMPOSITION COMPRISING A MAJOR PROPORTION OF AN OIL AND FROM ABOUT 0.0001% TO ABOUT 5.0% OF AN OIL-SOLUBLE ACIDIC HYDROLYZED REACTION PRODUCT OF A PHOSPHORUS SULFIDE AND A MEDIAL OLEFIN HAVING THE GENERAL STRUCTURE 